1. Field of the Invention
This invention relates generally to magnetic recording and/or reproducing apparatus, such as, cassette-type video tape recording and reproducing apparatus (VTR), and more particularly is directed to improvements in an automatic tape loading and unloading device for such apparatus.
2. Description of the Prior Art
Existing video tape recording and reproducing apparatus generally comprise a tape guide drum having a rotary magnetic head assembly associated therewith to record or reproduce video signals on a magnetic tape which is usually wound on supply and take-up reels with the tape between such reels being wrapped about at least a portion of the circumferential surface of the drum and being driven by a cooperating capstan and pinch roller and by suitable rotation of the take-up reel. In preparing such a video tape recording and reproducing apparatus for operation, the tape extending between the supply and take-up reels, which are preferably contained in a cassette, must be placed around or wrapped about at least a portion of the drum circumference so that the tape will be guided thereby with respect to the rotary magnetic head assembly.
In order to avoid the obvious disadvantages of manually withdrawing the tape between the reels from the cassette and threading the tape about the guide drum and the various other guide members and between the pinch roller and capstan in preparation for a recording or reproducing operation, and of manually removing the tape from the guide drum and returning the tape to the cassette at the completion of such an operation, automatic tape loading and unloading devices have been proposed for performing the foregoing functions.
One type of previously proposed automatic tape loading and unloading device for a video signal recording and/or reproducing apparatus, for example, as disclosed in detail in U.S. Pat. No. 3,821,805, issued June 28, 1974, and having a common assignee herewith, includes a support ring which is turnable around the guide drum in a substantially horizontal arcuate path that extends under the cassette when the latter is received and positioned by the holder therefor, tape engaging members including a pinch roller which project upwardly from the support ring so as to extend into an opening of the cassette for engagement with the tape therein when the ring is in an inactive or starting position, such tape engaging members drawing a loop of tape from the cassette and wrapping one side of the tape loop around the guide drum and between the pinch roller and a capstan upon turning of the ring to an operative position during a tape loading operation, and a tape guiding member mounted on the support ring and is moved relative to the latter from an inner position, at which the tape guiding member also extends upwardly into the cassette opening with the support ring at its inactive or starting position so as to be disposed within the tape loop, to an outer position spaced outwardly from the support ring in response to movement of the latter to its operative position during a loading operation, so that the tape guiding member then holds the other side of the tape loop away from the guide drum.
With a tape loading and unloading device of the type described above, the holder for the cassette has to include a table which is movable substantially vertically between a raised position, at which the table is above the tape engaging members on the support ring at its inactive position and also above reel drive members so that a cassette can be slidably installed on or withdrawn from the raised table, and a lowered position at which the tape engaging members project into the opening of the cassette positioned on the lowered table and the reel drive members also extend through openings in the table and cassette housing for engagement with the reels in the latter. Therefore, the existing tape loading and unloading device has to be associated with a relatively complicated cassette holder, for example, as disclosed in detail in U.S. Pat. No. 3,833,921, issued Sept. 3, 1974, and also having a common assignee herewith.